Electrically-operated hoisting apparatus.



F. B. LUTZ. ELE'GTRIGALLY OPERATED HOISTING APPARATUS.

Patented June 27, 1911.

2 BHEETB-BHEBT 1.

APPLICATION FILED JUHEB, 19091- INVEIVTM JTTQRIVEYS WI THE $61535 F. E.LUTZ.

ELEGTRIGALLY OPERATED HOISTING APPARATUS.

APPLICATION FILED JUNIH! 1909. 996,267. A Patented June 27,1911.

2 SHEETB-BHBBT 2.

INVE/Vmfl M BY WITNESSES:

"UNITED STATES PATENT OFFICE.

FRANK EDWARD LUTZ, OF PHILADELPHIA, PENNSYLVANIA.

ELECTBICALLY-OPERATED HOIS'I'NG APPARATUS.

Specification of Letters Patent. Patented June 27, 19 [1.

Application filed June 8,

1909. Serial No. 500,877.

To all whom it may concern:

Be it known that I, F RANK EDWARD LUTz, a citizen of the United States,residing at Philadelphia, county of Philadelphia, and State ofPennsylvania, have invented a new and useful Improvement inElectrically- O aerated Hoisting Apparatus, of which the to lowing is afull, clear, and exact description, reference being had to the accomanying drawings, which form a part 0 this specification.

My invention relates to certain iin rovements in limiting the movement 0machinery or apparatus propelled by electric motors, as, for instance,the limiting of the lifting or lowering of hoisting apparatus or thelimiting of the vertical or horizontal movement of other movingapparatus.

Particularly, the invention relates to a three point switch with switchblade pivoted at one point and the switch operating arm pivoted at thesame point and providing a projection or trip for opening the operatingarm. The switch may either be placed on the moving member and the tripon a fixed point or vice versa.

Further, the invention relates to certain electric circuits controlledby the switch, whereby in one osition of the switch the current can pass1n one or an opposite direction to the motor while in another positionof the switch it can pass in one direction only.

Further, as particularly applicable to a hoisting drum, it relates to atrip mounted upon the drum and having its operative po sition determinedby the winding of the rope upon the drum.

This, and certain details of construction of the trip and othermechanism, generally speaking, form the subject-matter of my invention.

I will now describe the embodiments of my invention as applied to ahoisting apparatus, as shown in the accompanying drawin and then pointout the invention in the c aims.

In the drawings: Figure 1 is a dis rammatic view of the electriccircuits. *ig. 2 is an elevation of a hoisting drum, etc. Fig. 3 is adetail view of switch and trip, etc.

Fig. 4 is a similar view with switch in another positicn. Fig. 5 is aside view of switch, etc Fig 6 1s an elevation of another view of trip.1g. 7 1s a plan view of trip of Fig. 6.

a isthe winding drum, 7) the motor, a a gear on the motor shaft, 65 alarge gear on shaft (2 with which gear a meshes, f a small gear on shaft0 meshing with gear g on drum shaft h.

j is the armature of the motor and 7c the field i l is the reversingswitch, in the lead wire from one pole of current supply and n the leadwire to the other ole. is interposed a contro ling switch having thespring cont-acts o and p in electrical conncction with wires of thecircuit. In addition to the contacts 0 and are the somewhat tightercontacts 9 an 'r, the pur ose of which will hereinafter be fully descried.

The switch proper consists of the blade 8 to which one wire of thecircuit connects and the circuit passes through the blade to the one ofthe contacts 0 or p to which the blade is connected. The blade ispivotally mounted at 19.

t are projections from the blade to each of which is connected a spring11.. The other ends of the s rings are connected to the de pending porons c of the yoke w. The yoke w is centrally connected to the arm 3 alsopivoted at w and having on its outer end the heart cam 2.

As may be seen, when the arm y is moved in one direction it throws oneof the springs u into tension and when the depending por- -,tion '0strikes the blade andmoves it sutliciently to free the blade from thecontacts, the tension of the spring is sufficient to snap the switchblade across the space between contacts and into electrical connectionwith the other contact. The springs, also, after this, bring theoperating arm to normal position.

The auxiliary spring cli s or contacts q and r insure the pro er ho dingof the contact with blade unti the action of the dcending portion 0positively ,moves the blade. This switch is mounted near to the drum sothatthe cam z is in line with a trip mounted on the drum in one positionof the trip. This trip consists of the trip proper 7 of heart shape onthe end of the arm 8, having the projecting tongue 9. The arm 8 ispivoted to the frame 10 and a spring 11 it normally in inoperativeosition. stand 10 is fixedly mounte so that the tongue 9 is in line withthe groove in the drum, so that the rope 200 entering this In thiscircuit connects the trip with the frame to retain The.

. .in Fig. 1, and the grooves ,drum can continue to descend.

groove will bear against this tongue and move the trip into alinementwith cam This tongue is generally placed in line with the groovecorresponding with a point just before the limit of the winding.

The controlling switch being in the position shown infull lines, Figs. 1and 3, and

osition shown eing free, the spring 11 holds the trip in the positionshown in Fig. 2. The current then passes through the circuit, Fig. 1, asindicated by the full arrows. The motor is then operated to rotate thedrum to wind the cable. \Vhen the cable reaches the groove in the drumin line with which the tongue on the trip rests the cable will move thetongue downwar against the action of the spring. This will bring the camof the trip in line with the cam of the switch as shown in Fig. 5.Further movement of the drum will cause the cam of the trip to move, thecam of the switch (see Fig. moving the arm and expanding one of t \e srings u. The blade will then be positive y moved by the dependingportion 4; of the okew until moved free from the auxiliary c ips v and rorfree from the clips when the springs will snap the blade across thegap to the opposite contacts. The springs wi 1 also return the o cratingarm to operative position when tie cam trip passes beyond it. Theposition of the arm and the blade in this position is shown in Fig. 4and the position of the blade in dotted lines, Fig. 1. With the blade inthis position shown in Fig. 1, no current will ass to the motor with thereversing switcii in its initial position for operating the reversingswitch in the the motor to rotate the drum-to wind the.

cable (see full arrows). When, however, the reversing switch is reversedto allow the motor to revolve to rotate the drum to unwind, the currentwill pass as indicated by the dotted arrows, Fig. 1. By this arrangement it is impossible, after the trip has actor], to operate thereversing switch except to cause the motor to operate in the oppositedirection, a. 0., to unwind the rope.

As soon as the drum moves to unwind, the tri i will act to operate thecontrolling switch ant bring it back to its initial position, Fig. l,the trip passing beyond the cam e of the arm 5: of this switch. Theblade then contactswith contact q. The wiring in this position is suchas to allow the current to continue to pass in the same direction aswith the blade in contact withcontact and the QVhen the rope passesfrolncontaot with the tongue of the tlipin the movcmcntof the drum to anwind, the spring moves thetrip to inoperative position where it remainsuntil again brought into action by the cable in the retation of the drumto ascend.

The trip device shown in Fig. 6 is one that may be used and has theadvantage over the trip shown in Figs. 3 and 4 in that of making certainthe return of the blade of the controlling switch, which would not occurin the switches of Figs. 3 and 4 if the tri failed to pass beyond thecam on the on of arm y. This trip consists of a. heartshaped cam 12 likethat of Figs. 3 and 4, which forms part of a frame 13 having a cut-awayportion between cam 12 and projection 14. This rojcctionhas a springblade 16 connected to its rear surface to which is connected a pin orprojection 17, projecting through an orifice ii -line with the activeface of cam 12. This frame 13 is pivoted to a bracket or frame 15 andalso connected thereto by spring 27. The frame 13 has also a tongue 18.The bracket is supported so that the tongue 18, like, the tongue 9 ofthe trip shown 1n Figs. 3 and 4, will be in line with a groove in thedrum. The frame 13 is brou ht into action by the cable pressing upon tietongue and moved out of action by the spring;

As may be seen, in the winding of thfeflrum if for any reason to the cam7 of should not pass beyond the cam z in t 0 reverse movement of thedrum, the in 1 will strike the cam a and bring the b ado of the controlling switch back to its initial position.

Havin now fully described my invention, what I c aim and desire toprotect by Letters Patent is 1. In an apparatus of the characterdescribed, a controlling switch device comprising. in combination, twocontacts, a pivoted switch blade adapted to swing from one contact tothe other, a pivoted arm, projections thereon, one adapted to engagesaid blade and move it from its position of tight engagement with onecontact toward the other contact, and the other adapted to engage saidblade and move it from its position of tight engagement with the secondcontact toward the first contact, and a. spring connccting said arm andsaid blade adapted to be thrown into tension during the movement of thearm until one of its projections engages and releases the blade andtethereafter snapsaid blade into engagementwith the other contact.

the cam 12, corresponding the trip of Figs, 3 and 4,

2. In an apparatus of the character de scribed, a controlling switchdevice (asap 1S-' ing, in combination, two contacts, a 1 0 d switchblade adapted to swing from one contact to another an arm pivoted onthe'axis of the switch blade and normally occupying a position parallelthereto when the switch blade is engaged with either contact, means toswing said arm from one to the other of its normal positions, asgringconnecting said arm and blade adapts to be thrown into tensionduring the swinging movement of the arm, and means on thearmadapted'during its movement to engage and move said blade out of tightengagement with its contactthereby permitting the spring to act to throwsaid blade into engagement with the other contact.

3. In an apparatus of the character described, a controlling switchdevice comprising, in combination, two contacts, a pivoted switch bladeadapted to swing from one contact to another, an arm pivoted on the axisof the switch blade and normally occupying a position parallel theretowhen the switch blade is engaged with either contact, means to swingsaid arm from one to the other of its normal positions and projectionscarried on opposite sides of said arm and springs connecting said bladewith the res ective projections, said blade being in line 0 travel ofone of said projections when the arm is swung as aforesaid; whereby theblade is first moved from tight engagement with one contact by means ofsaid projections and then snapped toward the other contact by the springthat is thrown into tension during the movement of the arm..

4. In an apparatus of the character described, a controlling switchcomprising, in

combination, two sets of contacts. each comprising a contact adapted tohold the switch blade relatively loose and one to hold it relativelytight, a pivoted switch blade adapted to swing from one set of contactsto another, a pivoted arm, projections thereon adapted, toward thecompletion of the swinging movements of the arm, to engage said bladeand release it from the tight contacts respectively, and a springconnecting the arm and the blade adapted to be thrown into tensionduring the movement of the arm to snap the blade, after its release froma tight contact, out of engagement with the corresponding loose contactand into engagement with the other set of contacts.

In testimony of which invention, I have hereunto set my hand, atPhiladelphia, on this 4th day of June 1909.

FRANK EDWARD LUTZ.

Witnesses M. M. HAMILTON, A. M. URIAN.

